calcium homeostasis; calcium sensor; neurodegnerative disease; adult neurogenesis; calcium-binding proteins; neurological diseases; calcium homeostasome; compensation mechanisms; transgenic mice; behavior
Pecze László, Schwaller Beat (2015), Characterization and modeling of Ca(2+) oscillations in mouse primary mesothelial cells., in Biochimica et biophysica acta
, 1854(3), 632-45.
Blum Walter, Pecze László, Felley-Bosco Emanuela, Worthmüller-Rodriguez Janine, Wu Licun, Vrugt Bart, de Perrot Marc, Schwaller Beat (2015), Establishment of immortalized murine mesothelial cells and a novel mesothelioma cell line., in In vitro cellular & developmental biology. Animal
, Online First Article, nn.
Wöhr M, Orduz D, Gregory P, Moreno H, Khan U, Vörckel K J, Wolfer D P, Welzl H, Gall D, Schiffmann S N, Schwaller B (2015), Lack of parvalbumin in mice leads to behavioral deficits relevant to all human autism core symptoms and related neural morphofunctional abnormalities., in Translational psychiatry
, 5, 525-525.
Blum Walter, Schwaller Beat (2013), Calretinin is essential for mesothelioma cell growth/survival in vitro: A potential new target for malignant mesothelioma therapy?, in International journal of cancer. Journal international du cancer
, 133(9), 2077-2088.
Pecze László, Blum Walter, Schwaller Beat (2013), Mechanism of capsaicin receptor TRPV1-mediated toxicity in pain-sensing neurons focusing on the effects of Na(+)/Ca(2+) fluxes and the Ca(2+)-binding protein calretinin., in Biochimica et biophysica acta
, 1833(7), 1680-1691.
Arendt Oliver, Schwaller Beat, Brown Edward B, Eilers Jens, Schmidt Hartmut (2013), Restricted diffusion of calretinin in cerebellar granule cell dendrites implies Ca2+-dependent interactions via its EF-hand 5 domain., in The Journal of physiology
, 591(16), 3887-3899.
Albéri Lavinia, Lintas Alessandra, Kretz Robert, Schwaller Beat, Villa Alessandro E P (2013), The calcium-binding protein parvalbumin modulates the firing 1 properties of the reticular thalamic nucleus bursting neurons., in Journal of neurophysiology
, 109(11), 2827-2841.
Todkar Kiran, Scotti Alessandra L, Schwaller Beat (2012), Absence of the calcium-binding protein calretinin, not of calbindin D-28k, causes a permanent impairment of murine adult hippocampal neurogenesis., in Frontiers in molecular neuroscience
, 5, 56-56.
Christel Carl J, Schaer Raphael, Wang Shiyi, Henzi Thomas, Kreiner Lisa, Grabs Detlev, Schwaller Beat, Lee Amy (2012), Calretinin regulates Ca2+-dependent inactivation and facilitation of Ca(v)2.1 Ca2+ channels through a direct interaction with the α12.1 subunit., in The Journal of biological chemistry
, 287(47), 39766-39775.
Ducreux Sylvie, Gregory Patrick, Schwaller Beat (2012), Inverse regulation of the cytosolic Ca²⁺ buffer parvalbumin and mitochondrial volume in muscle cells via SIRT1/PGC-1α axis., in PloS one
, 7(9), 44837-44837.
Olinger Eric, Schwaller Beat, Loffing Johannes, Gailly Philippe, Devuyst Olivier (2012), Parvalbumin: calcium and magnesium buffering in the distal nephron, in NEPHROLOGY DIALYSIS TRANSPLANTATION
, 27(11), 3988-3994.
Moreno Herman, Burghardt Nesha S, Vela-Duarte Daniel, Masciotti James, Hua Fan, Fenton André A, Schwaller Beat, Small Scott A (2012), The absence of the calcium-buffering protein calbindin is associated with faster age-related decline in hippocampal metabolism., in Hippocampus
, 22(5), 1107-1120.
Schwaller Beat (2012), The use of transgenic mouse models to reveal the functions of Ca(2+) buffer proteins in excitable cells., in Biochimica et biophysica acta
, 1820(8), 1294-1303.
Lintas Alessandra, Schwaller Beat, Villa Alessandro E P, Visual thalamocortical circuits in parvalbumin-deficient mice., in Brain research
Ca2+ signaling is a key mechanism for various biological processes such as cell growth, cell division, differentiation and cell death. It operates on a huge range of time scales (ms to h) and magnitudes (nM to mM). For this, cells make use of various proteins from the “Ca2+ signaling toolkit” comprising proteins involved in Ca2+ entry/extrusion (channels/pumps) from either the extracellular space or from intracellular compartments (endoplasmic reticulum, mitochondria) and specific Ca2+-binding proteins acting as intracellular modulators of Ca2+ signals. Each cell type expresses a particular set of the various components involved in Ca2+ handling/signaling defined as the “Ca2+ signalsome”; when considering that these molecules are not only functionally linked, but likely also regulated in a network-like fashion, the term “Ca2+ homeostasome” has been proposed. In view of the large complexity of Ca2+ signaling, it is not surprising that the malfunctioning or disruption of intracellular Ca2+ homeostasis has been associated with ageing, neurodegeneration and various diseases collectively termed “calciumopathies” that includes epileptic seizures, migraine, bipolar disorder and autism, to name a few. While genetic mutations in Ca2+ channels or Ca2+-regulated channels were identified in calciumopathy patients, none have been identified so far for the family of intracellular Ca2+-binding proteins including parvalbumin (PV), calbindin D-28k (CB) and calretinin (CR). However, altered expression (most often a down-regulation) has been observed in postmortem brains of patients with various diseases. Currently it is not known whether these changes are causally linked to the disease or the result of an adaptive/protective mechanism brought about by the Ca2+ homeostasome. Thus, the aim of this proposal is to better understand the web of intracellular Ca2+ signaling/regulation using transgenic mice with altered expression of these Ca2+-binding proteins.A) In this subproject we will investigate the putative Ca2+ sensor function of CR. The experiments are based on our findings that I) CR is able to interact with intracellular parts of specific Ca2+ channels in vitro and II) the presence of a putative LD domain, a protein-interacting domain present in several structural and functional proteins such as paxillin. The transient expression of CR during adult neurogenesis in the hippocampus linked to differentiation and expression of specific transcription factors (e.g. basic helix-loop-helix proteins) is another indication of CR’s putative Ca2+ sensor function.B) Initial experiments on the behavior of PV knockout mice indicate that PV’s absence could be causally related to one of the presumed calciumopathies: autism spectrum disorder (ASD), where altered Ca2+ signaling is suggested as a possible molecular mechanism. A detailed behavioral investigation of PV-/- mice is the core of this subproject.C) The functioning of the Ca2+ homeostasome is investigated at two levels: at the cellular level in a muscle cell line where PV levels are modulated by genetic methods and in muscle fibers from PV-/- and wildtype mice. We will determine the functional consequences of the observed increased mitochondria volume in PV-/- fast-twitch muscles with respect to Ca2+ handling, but also determine which Ca2+-dependent processes lead to these adaptive or homeostatic changes. At a systemic level, the role of the Ca2+-binding proteins PV, CB and calbindin D-9k in the fine-tuning of divalent cation (Ca2+, Mg2+) resorption and secretion in the kidney will be investigated by different methods including Gene Chip Analysis.In conclusion, the Ca2+-binding proteins PV, CB and CR likely play important roles in many processes in the brain, muscles and in the kidney and their absence or downregulation in humans and animal models leads to changes detectable at various levels. The projects of this proposal are not exclusively aimed to better understand the protein’s physiological roles, but to explore the regulation of the Ca2+ homeostasome, of which these proteins are an integral part. We think that this will eventually lead to a better understanding of various diseases (calciumopathies) and possibly ageing, in which alterations in Ca2+ signaling are thought to be causally involved.